Lapping machine



April 13, 1937. A. J. STRONG LAPPING MACHINE Filed April 18, 1935 7 Sheets-Sheet l ATTORNEYS April 13, 1937.

A. J. STRONG LAPPING MACHINE Filed April 18, 1955 7 Sheets-Sheet 2 ATTO RN EYS April 1937. A. J. STRONG 2,076,601

LAPPING MACHINE Filed April l8, 1935 7 Sheets-Sheet 5 April 13, 1937. A. J. STRONG v LAPPING MACHINE 7 Sheets-Sheet 4 Filed April 18, 1935 ATTORNEYS April 13, 1937. J STRONG 2,076,601

I LAPPING MACHINE Filed April 18, 19s5-' 7 Sheets-Sheet s INVENTOR ATTORNEYS April 13, 1937. J STRQNG' 2,076,601

LAPPING MACHINE Filed April 18, 1955 7 Sheets-Sheet 6 ATTORNEYS 13, 1937. A, ,,STR NG 2,076,601

LAPPING MACHINE Filed April 18, 1935 7 Sheets-Sheet 7 INVENTOR I ATTORNEYS Patented Apr. 13, 1937 UNITED STATES PATENT OFFICE LAPPING MACHINE Arthur J. Strong, Highland Park, Mich.

A plication April 18, 1935, Serial No. 16,984

v {Claims (Cl. 51-58) The present invention pertains to a novel lapping machine for providing smooth surfaces on various parts to be finished. V

I The primary object of the present invention is to provide a machine for lapping annular pieces of work, such as bearing races, rapidly and emciently, the machine comprising means for receiving and supporting the work in contact with a tool and means for causing rotation of the work while it is in contact with the tool, the means for receiving and supporting the work being constructed to permit rapid removal and replacement of the work thereon.

Another object of the present invention is to provide a lapping machine comprising an adjustably movable tool supporting carriage and a constantly rotating frictional driving element, the tool carriage having means for placing work thereon in contact with the tool and suitable means for moving the tool carriage to cause contact between the work and the driving element whereby the latter causes rotation of the work. In connection with the movable carriage it is a further object of the invention to provide resilient means between the point of application of the pressure and the tool so as to render the machine fool proof to the extent that it is impossible to apply an excessive amount of pressure on the tool with resulting damage to the work. In connection with the frictional work driving element it is another object of the present invention to provide adjustable means for oscillating the same as it is rotated in order that it may cause the work to oscillate as it is rotated in contact with the tool.

Another important object of the invention is to provide a novel driving element for rotating work in contact with a tool, the driving element comprising spaced apart disks between which the edge of the part to be rotated is interposed and resilient pressure means associated with the disks for causing them to grip the work with suflicient friction to cause rotation of the work. Although the driving element is particularly adapted for use in combination with annular parts such as bearing races it is illustrated by way of modified showings that it is not confined to this use alone. Another object of the present invention is to 50 provide, in a lapping machine, a tool support for accommodating a plurality of tools, the support being easily movable for the purpose of interchanging tools and thus making it possible to provide different grades of tools which may be 55 used selectively without necessitating re-tooling operations in order to provide for the use of light lapping or heavy roughing lapping.

Another object of the present invention is to provide a tool support embodying means for compensating for wear of the tool, and in' the event 5 that the work is oscillated while it contacts with the tool the said compensating means is constructed to permit a limited amount of pivotal movement of the tool relative to its support.

Another object of the invention is to provide 10 a lapping machine embodying a rotatable driving element and means for supporting tools whereby both the inner and outer surfaces of an annular element may be lapped simultaneously.

Still another object of the present invention 15 is to provide an adapter for use with work having no part suitable for engagement by the present frictional driving element, the adapter being constructed to permit its rapid assembly on the work and its removal therefrom. 20

Figure 1 is a front elevation, partly broken away, and in cross section;

Fig. 2 is a side elevation;

Fig. 3 is a cross section taken on the line 3-3 of Fig. 1; 5

Fig. 4 is an end elevation of a modified tool support;

Fig. 5 is a cross section taken on the line 5-5 of Fig. 4;

Fig. 6 is an end elevation illustrating a modi- 30 fled tool supporting carriage;

Fig. '7 is a cross section taken on the line 1--'I of Fig. 6;

Fig. 8 is a cross section taken on line 8--8 of Fi 7; 35

Fig. 9 is a cross section taken on line 9-9 of Fig. 6;

Fi 10 is a cross section taken on line |0--I0 of Fig. 9;

Fig. 11 is a cross section taken on line Il-l I 40 of Fig. 10;

Fig. 12 is a fragmentary plan illustrating tools for internal and external lapping;

Fig. 13 is' a plan illustrating a modified tool support;

Fig. 14 is a side elevation relating to Fig. 13

Fig. 15 is a plan of another modified form of tool support;

Fig. 16 is a plan view of a tool and means f0 lapping valve stems; I

Fig. 1'7 is a plan view of an arrangement embodying a tool for lapping a substantially spherical piece of work;

Fig. 18 is an elevation corresponding to Fig. 17;

Fig. 19 is a detail of an adapter for use with work such as shown in Fig. 17, and

Fig. 20 is a cross section taken on the line 28-28 of Fig. 19.

Like characters of reference are employed throughout to designate corresponding parts.

With reference more particularly to Figs. 1 and 2 there is shown a machine comprising a base I rotatably supporting a sleeve 2 having a pulley 3 connected by a belt 4 to a pulley 5 on the shaft 8 of a motor I. Splined or slidably keyed within the sleeve 2 is a shaft 8 having a collar 9 secured to one end thereof and receiving the forked end l8 of a lever H which is pivoted intermediate its ends to a bracket 2 secured on the base I. The opposite end of the lever II is connected by a link l3 to a pin l4 which issecured in a slot l5 in a disk l8, the pin l4 being movable in the slot for the purpose of adjusting the same to a position co-axial with the disk or eccentric thereto. The disk l8 has a worm gear I! connected thereto which meshes with a worm gear |8 on a shaft l9 carrying a pulley 28. The pulley 28 is connected by a belt 2| to a pulley 22 on the sleeve 2.

At the stage of the description it will be understood that the shaft 2 is driven by the motor I and imparts rotation to the shaft 8. The disk I8 is likewise rotated through worm l8, gear I'I, pulley 28 and belt 2|, and in rotatingwith the pin l4 adjusted to a position eccentric thereto causes lever II to rock and to oscillate shaft 8. The purpose of such oscillatory movement will become apparent as the description progresses.

Secured to the other end of the shaft 8 is a frictional driving element comprising a collar 23, the means for securing the collar being shown by way of example as a set screw 24 engaging a fiat 25 on the shaft 8 as more clearly shown in Fig. 3.

Secured by screws 28 to the collar 23 is a disk 21 having a flange 28, this disk preferably being formed of flbrous material. Secured on'the shaft 8 by a set screw 29 is a collar 38 and a disk 3|, also of fibrous material, is loosely interposed between the disk 21 and the collar 38, the disk 3| being free to rotate relative to the shaft 8 and free to move longitudinally a limited amount between the disk 21 and the collar 38. The collar 38 has a series of holes 32 receiving coiled springs rest 48 and in operation the work 4|, shown by way of example as a bearingrace, is placed over the tool 39 and is forced, by movement of the carriage 35, between the flange 28 and the disk 3| as shown in Fig. 3. when the edge of the work is forced between the flange 28 and disk 38 the work is caused to be rotated in contact with the tool 39 and in the event that the pin I4 is set eccentric as above described the work will also be caused to oscillate. In order to permit oscillation of the work it is necessary that the tool 39 be permitted to pivot and in order to provide for such pivotal movement the tool is loosely mounted in a slot 42 which is of greater width than the tool. A slidable block 43 is mounted in the slot and has a ridge 44 engaging the rear end of the tool to back it, the block 43 being held against movement by a set screw 45.

In order to move the tool carriage to carry the work into and out of engagement with the flange 28 and disk 3| there is provided a gear wheel 48 on the carriage bracket 34, the gear wheel meshing with rack teeth 41 on the carriage 35. A lever 48 has a foot treadle 49 on its lower end and is pivotally secured by a removable pin 58 to a bracket 5| on the base I. On the upper end of the lever 48 is provided a gear segment 52 meshing with gear 48 so that rocking of lever 48 through manual pressure on the treadle 49 causes gear 48 to rotate and the carriage 35 to move to and -fro. Between movements of the carriage a piece of work 4| may be easily removed and another piece substituted therefor.

In Figs. 4 and 5 there is shown a modified means of supporting a lapping tool and it will be understood that when this form of tool support is used the pin I4 is adjusted to a point concentric with the disk l8 to eliminate oscillation of shaft 8 in the event that the work piece has an arcuate cross section such as the work piece shown at 4|. In the event that the work has a flat surface, it will be understood that the shaft- 8 will be caused to oscillate as above described. In detail, the work support of Figs. 4 and 5 comprises a head 53 having its end notched as at 54 to receive a tool 55. Secured in a recess 580 by a set screw 51a is a clamping plate 580 which clamps the tool 55 in the notch 54. In use, the head 58 is mounted on a carriage such as the carriage 35 described above. v

With reference to Figs. 6, 7, 8 and 9 there is shown a modified arrangement comprising a driving shaft 58 which is the equivalent of shaft 8 in the above described embodiment. 0n the shaft 58 is formed a flange 51 to which is bolted a fibrous disk 58 having a flange 59. Loosely received on the shaft 58 is a fibrous disk 88 which is loosely tied to the disk 58 by a series of pins 8|. Under heads 82 on the pins 8| are placed coiled springs 83 which are received in metal inserts 84 in holes 85 in the disk 58. The springs 83 exert resilient pressure on the pins 8| tending to draw the disk 88 toward the disk 58.

On a carriage bracket 88 is supported a draw able tool carriage 81 having a guide block 88 bolted thereto. Slidably received on the block 88 is a tool support housing 89 having end plates 18 and II secured theretoto limit the. sliding movement of the housing relative to the guide block. The guide block 88 has a lengthwise extending bore 12, screwthreaded at the end adjacent to end plate II to receive a screwthreaded plug 13 which may be adjusted through an aperture 14 in the plate 'II.- In the end plate 18 is secured a bolt 15 to extend into the bore 12 and between the end of the bolt 15 and the plug 13 is interposed a compressed coiled spring 18. On the housing 89 is'provided a bearing "a receiving a tooLsupport II, the latter being slidable relative to the bearing and having collars l8 and 19 for limiting the sliding movement thereof and means indicated at 88 for attaching mechanism thereto for moving the same. 0n the tool support I1 is provided a head 8| having slots 82 formed therein in spaced relation, this construction being more clearly shown in Figs. 10 and 11. In the slots are slidably received blocks 83 and set screws 84 are mounted in the head to engage the blocks 88 to hold them in adjusted positions. In each slot is provided a lapping tool .85 narrower than the slot in which it is received. Each tool has a groove 88 in the end thereof to engage a projection 81 on the adjacent block "and a hole 88 receiving a coiled spring 89 which presses against the wall of the slot to offer a small resistance to movement of the tool in the slot. At the forward end of each slot is provided a "Carboloy. insert 90 to eliminate, as much as possible, wearing away of the wall of the slot.

'5 As will be observed with reference to Fig. each slot has two set screws 84 arranged so that as the tool 85 wears away through use the block 83 may be advanced and held by first one and then the other of the set screws.

10 On the housing 69 is provided an outwardly extending work support 9| and in operation the work 92 is placed on one or other of the tools 85 and the carriage 61 ismoved so as to carry the work into engagement with the flange 59 and disk 60 which cause the work to rotate. By shifting the tool support 11 longitudinally from its illustrated position to a position where collar I8 limits further movement the other tool will be brought into an operative position. The construction thus provides for the use of two different grades of tools.

It is contemplated that manual means, an example of which is disclosed above, will be employed to move the carriage to cause engageiment of the work with the driving disks. The pressure of the means for moving the carriage is transmitted to the tool support housing through the coiled spring I6 and therefore the device is fool proof to the extent that an excessive amount of pressure on the manual means will not be transmitted to the tool support.

On the movable carriage 61 is mounted a bearing block 93 supporting two spaced apart spools 94 around which is woun an abrading ribbon 3 95, the ribbon being trained over the work support 9I so that the outside surface of the work contacts therewith. Connected to one of the spools 94 is a ratchet wheel 96 cooperating with a spring pressed pawl 91 on a rod 93 whose end is attached to a stationary part 99 secured to the carriage bracket 66. Each time the carriage 61 is moved to carry a piece of work out of engagement with the driving disks and another piece of work into engagement with the driving disks the pawl advances the pulley to which the ratchet 96 is attached so as to present a fresh part of the ribbon 95 for engagement by the work. In Fig. 12 there is illustrated an arrangement for lapping both the inner and outer surfaces of a piece of work. In this embodiment the driving disks are constructed as particularly described above and are generally designated by the numeral I00. Adjacent to the driving means I00 is a carriage bracket IOI supporting two separately movable tool carriages I02 and I03. On

the carriage I02 is mounted a tool support housing I04 and on the carriage I03 is mounted a tool support housing I05, the two housings I04 and I 05 being flexibly mounted relative to their respective carriages in the manner described above with reference to the tool support housing 69. On the housing I04 is provided a tool support I06 having a lapping tool I01 adapted to engage the inner surface of a piece of work I08 and to hold it in contact with the drivingmeans I00. 0n the carriage I05 is provided a tool support I09 having a pivoted head H0 in which is secured a lapping tool III. Due to the fact that the inner surface of the work is flat and the head H0 is pivoted the driving means I00 may be oscillated as it is rotated in the manner more particularly described above.

In Figs. 13 and 14 there is illustrated a tool 75 support II2 having a spindle II3 rotatably receiving a head H4 and a set screw II5 for holding the head against rotation relative to the spindle. In the head are secured tw'o lapping tools II6 adapted to be positioned for use in lapping a piece of work by rotating the head on the spindle. In Fig. 15 is illustrated a tool support similar in principle wherein tools I" are secured to a rotatable head II8 by clamping plates H9. In this latter form-either tool may be moved into cooperative relationship with the work I20 and is used, as is also the device of Figs. 13 and 14, for external lapping.

In Fig. 16 there is illustrated a driving shaft I2I having a plurality of idle rollers I22 thereon and a driving means I23 constructed as described above. An elongated lapping tool I24 is supported on the tool support hearl I25 and engages the stem I26 of a valve I 21, the valve I2I being'held by the tool in engagement with the driving means I23.

In Figs. 17 to 20 inclusive there is illustrated an embodiment wherein the invention is adapted to lapping the ball end I28 of a steering arm I29. In this embodiment the tool I30 is mounted in a sleeve I3I which is secured, by a set screw I32 on an arm I33 on a tool support housing I34. The

sleeve I3I has diametrically opposite slots I35 and set screws I36 extend through the slots to engage a sleeve I3I which engages the end of the tool I30. The ball end I 28 is held between an idle roller I38 and the tool I30 and the arm I29 rests upon a suitable support I39, the idle roller I38 being supported by a drive shaft I40 carrying driving means I4I. An adapter I42 has a bore I43 permitting it'to he slipped onto the end I44 of the steering arm and a spring pressed wedging member I45'is mounted in the adapter to frictionally engage the part I44 to hold the adapter against rotation. The adapter is adapted to engage the driving means I4I to cause rotation of the steering arm I29.

Although specific embodiments of the invention have been illustrated and described it will be understood that various changes may be made in the details of construction without departing from the spirit of the invention as set forth in the appended claims, and such changes are contemplated.

What I claim is:

1. In a lapping machine, a rotatable shaft, a pair of friction disks mounted on said shaft with one of said disks secured to said shaft, the other of said disks being longitudinally movable relative to said shaft, and resilient means normally urging said disks together.

2. In a lapping machine, a rotatable shaft, a pair of friction disks mounted on said shaft with one of said disks secured to said shaft, the other of said disks being longitudinally movable relative to said shaft, resilient means normally urging said disks together, a movable tool support, means on said support for receiving a piece of work, and means for moving said support to move the edge of the work between said disks.

3. In a lapping machine, a constantly rotatable frictional driving means, means for oscillating said frictional driving means, a movable tool support, means on said tool support for receiving a piece of work, and means for moving said support to move said work into engagement with said driving means.

4. In a lapping machine, a constantly rotatable frictional driving means, means for oscillating said frictional driving means, a movable 10 whereby said tool carries said work into engagement with said driving element, and a resiliently yieldable element between the manual means and the tool.

6. In a lapping machine, a rotatable shaft, a 15 pair of friction disks mounted on said shaft to rotate therewith; said disks being relatively movable longitudinally of said shaft, resilient means normally urging said disks together, and rigid means between said disks maintaining them spaced apart.

'7. In a lapping machine, a rotatable shaft, a pair of friction disks mounted on said shaft to rotate therewith, said disks being relatively movable longitudinally of said shaft, resilient means.

normally urging said disks together, and rigid means between said disks maintaining them spaced apart, said rigid means having a circular.

contour whereby it provides an abutment for work placed between said disks.

ARTHUR J. STRONG. 

